Coalition members, especially the larger parties, are expected to have demanded concessions, including ministerial posts in the cabinet.
The swearing-in ceremony will be held at the presidential palace in New Delhi on Sunday evening at 13:45 GMT while the prime minister has yet to announce who will be serving on his cabinet.
Modi’s Hindu nationalist Bharatiya Janata Party (BJP) garnered 240 seats, but fell 32 short in the 543-member lower house of parliament, registering its weakest showing in after a decade of dominating Indian politics.
Leaders of the 15-member coalition, called the National Democratic Alliance (NDA), who provided him with the required numbers to govern for a third five-year term, started negotiations in New Delhi earlier this week.
Coalition members, especially the larger parties, are expected to have demanded concessions from Modi, including ministerial posts in the cabinet. Modi’s previous cabinet had 81 ministers.
The Hindustan Times described days of “hectic talks”, while The Times of India said the BJP had sought to “pare down” their partners’ demands.
‘Meeting his match’
The Telugu Desam Party (TDP) is the largest BJP ally with 16 seats, and is widely reported to have secured four cabinet positions. The party is led by 74-year-old veteran politician and three-time chief minister Chandrababu Naidu, and dominates politics in the southern coastal state of Andhra Pradesh.
The Janata Dal (United) party is next in line, having secured 12 parliamentary seats. Its leader, 73-year-old Nitish Kumar, is known for having changed political allegiances in the past to suit his interests, having abandoned the opposition and switching to Modi’s side weeks before the election.
Analysts said that the coalition will shift parliamentary politics and force Modi’s once domineering BJP into a somewhat more conciliatory approach.
“In the past, the BJP has had confidence because of its sheer majority,” said Sajjan Kumar, head of the New Delhi-based political research group PRACCIS. “The coalition will now force the BJP to engage in more consultation.”
Zoya Hasan of the Jawaharlal Nehru University said Modi faced potential challenges ahead – warning he may be “meeting his match” in the “crafty politicians” of the TDP’s Naidu and JD(U)’s Kumar.
Indian media have reported that Modi will assign his own trusted BJP figures to the top posts in the cabinet, including the interior, foreign affairs, finance and defence ministries.
Security was tight in the capital on Sunday, with thousands of troops and police deployed as regional leaders flew in.
Bangladeshi Prime Minister Sheikh Hasina and Sri Lankan President Ranil Wickremesinghe – as well as leaders including those of Bhutan, Nepal and the Maldives – are due to attend the ceremony and the following state banquet.
Neighbouring rivals China and Pakistan are notably absent in not sending a top leader.
Meanwhile, Rahul Gandhi, a descendant of top Indian politicians from the Congress party that led the alliance competing with Modi, is expected to be recognised as the country’s official opposition leader.
The position has been vacant for a decade because the BJP had dominated the previous two elections, leaving the Congress – once India’s dominant party – short of a threshold.